This invention relates to telecommunications and, more particularly, to methods for establishing a communication path between parties.
The classic technique for establishing a communication path between two parties involves a caller, say Bob, obtaining the phone number of a called party, say Mary. Bob dials Mary's number and the network establishes a connection. In this classical methodology there is a known, fixed, relationship between Mary and her phone number. The only way for Mary to maintain anonymity or to be selective as to whom she would accept as a caller is to keep her phone number secret from most people. But even that is not as effective as may be desired because callers can just happen to select Mary's number and, also, once the phone number is given the information cannot be retrieved.
In connection with accepting of calls, Mary can subscribe to a "Caller ID" feature where, during the ringing interval, Mary is shown the phone number of the caller. That allows Mary to choose whether to answer the call or not. However, the "Caller-ID" feature fails to preserve Mary's tranquillity because all incoming calls still ring at Mary's phone.
Another form of selectivity is attained when Mary has more than one telephone number and gives out different numbers to different people. This, alas, has the disadvantage of requiring Mary to have--and pay for--a number of different telephone numbers, and each telephone number corresponds to a different end point in the telephone network. Even in the more sophisticated arrangements where the phone number is not fixedly associated with a network end point, and the number of end points may, therefore, be less than the number of phone numbers that Mary calls her own (e.g., the recipient, Mary, has a conventional number and an 800 number that translates to the same conventional number), there is still a charge that is levied on Mary for each number. Moreover, the relationship between the known numbers and the identity of the user is effectively fixed, since it is impractical to dynamically establish and/or revoke existing telephone numbers. If Mary tells somebody her private number, she cannot revoke that number a week later without interacting with the service supplier to obtain a new number. Additionally, she needs to divulge her new number to those who she wants to know the new number. Because of the cost, the number of different phone numbers that Mary might maintain is typically quite small.
What is desired is an arrangement where a recipient can have a more flexible interface to the world: an interface where different callers may have different permissions for accessing Mary and where, at will, Mary can generate or revoke calling permissions.
In the field of electronic mail, there exist remailers that facilitate communication while providing various types of enhanced privacy. In one mode, a sender, say Joe, having established an account with the remailer, sends a message to the remailer. This includes instructions on how the body of the message is to be delivered. The remailer removes from the incoming message the usual fields that identify the sender, substitutes a pseudonym, and forwards the body to the requested destination(s). The intended application of such services includes, for example, people who wish to "blow the whistle" on misconduct by their employer, government, etc. The reverse service also exists, whereby Joe can establish an alias at a remailer, so that mail addressed to that alias will be forwarded to Joe. This allows him to receive messages on controversial subjects (see, for example: http://www.well.com/user/abacard/remail.html).
For that matter, in the field of conventional postal service, letter drops, parcel drops, and remailers have existed for years. Among other things, such services allow people to communicate without, for instance, divulging their home addresses.
Remailer service is obviously attractive to criminals, and service operators typically take steps to discourage this.